#include<cstdio>//uncle-lu
#include<algorithm>
template<class T>void read(T &x)
{
	x=0;int f=0;char ch=getchar();
	while(ch<'0'||ch>'9') { f|=(ch=='-'); ch=getchar(); }
	while(ch<='9'&&ch>='0') { x=(x<<1)+(x<<3)+(ch^48); ch=getchar(); }
	x = f ? -x : x;
	return ;
}

int F[40][40];
int n,m;

int main()
{
	read(n);read(m);

	for(int i=1;i<=m;++i)
		F[1][i] = i+1;
	for(int i=1;i<=n;++i)
		F[i][1] = i+1;

	for(int i=2;i<=n;++i)
		for(int j=2;j<=m;++j)
		{
			F[i][j] = F[i-1][j] + F[i][j-1];
		}

	printf("%d",F[n][m]);

	return 0;
}
